Process for production of carbon disulfide



June 12, 1951 B. w. GAMSON PROCESS FOR PRODUCTION OF CARBON DISULFIDE Filed Aug. 17, 1948 mm as \v hum A T TOP/V576 ture range.

Patented June 12, 1951 PROCESS FOR PRODUCTION OF CARBON DISULFIDE Bernard W. Gamson, Morton Grove, Ill., assignor to Great Lakes Carbon Corporation, Morton Grove, 111., a corporation of Delaware Application August 17, 1948, Serial No. 44,657

This application relates to a process for producing carbon disulfide.

In my copending applications Serial Numbers 546,427, filed July 24, 1944, and 649,730, filedFebruary 23, 1946, now U. S. Patents Nos. 2,447,003 and 2,447,004, respectively, are described processes for producing sulfocarbons and sulfohydrocarbons and a process for making carbon disulfide from the sulfocarbon. The present invention relates to an improvement in the process for producing carbon disulfide from sulfocarbons.

In accordance with the process described in the above applications, sulfocarbons in general are made by mixing a heavy hydrocarbonaceous substance with elemental sulfur at a temperature in the range of about 425-625 F. to produce a reaction product which is liquid within said tempera- This material is then heated at a temperature above about 625 F. but below about 1800 F. to'produce a hard, black, amorphous, infusible, insoluble substance.

Depending upon the temperature to which the mixture is heated, the material is either a sulfohydrocarbon or a sulfocarbon of the composition given in the above mentioned application. The sulfocarbons are particularly useful in the production of carbon disulfide by reacting them with elemental sulfur vapors at a temperature of about 11004800 F.

According to a broad embodiment the present invention comprises forming a liquid mixture of elemental sulfur and a hydrocarbonaceous substance liquid in the range of about 425-625" F;

at atmospheric pressure, injecting the liquid mixture in the form of droplets into a heated reaction zone at a temperature above 625 F. to convert the droplets into solid particles of sulfohydrocarbons and/ or sulfocarbons, said particles being maintained in a fluidized condition, withdrawing said particles continuously, mixing them with sulfur vapor and injecting them intoa car'- bon disulfide reaction zone at a temperature in the range of about 1l00-1800 F., maintaining the particles in a fluidized condition within said carbon disulfide reaction zone, removing vapors comprising carbon disulfide and hydrogen sulfide therefrom, fractionating the vapors to separate the carbon disulfide from the hydrogen sulfide, recovering carbon disulfide, oxidizing the hydrogen sulfide to elemental sulfur and recycling the elemental sulfur.

The invention may be understood by reference to the accompanying drawing of which the following is a description and which diagrammatically illustrates the various process steps. A heavy hydrocarbon in liquid form is introduced through line I, valve 2, pump 3, line 4, valve 5,, to line 6 and valve ,1 into a. mixer .8... .A. heat;

- 6 Claims. (Cl. 23206) exchanger or other suitable preheater 9 may be contained in line 4 to preheat the oil within a temperature range of about 300-625 F. Elemental sulfur is introduced through line H], line H, line I2, and valve l3 joining with line 6 and being mixed with oil from line 4. The sulfur may be molten, or may be added in any convenient way to produce a uniform mixture with the hydrocarbon.

The hydrocarbon may be any heavy hydrocarbonaceous substance having a boiling point above 350 F. and being liquid in the range of about 400-625 F. Suitable stocks are heavy straight run or cracked petroleum residues, topped or reduced crude oils, coal tar oils, shale oils and the like. For the best results the oil should have a hydrogen content of from about 4 to 12%.

The amount of sulfur added to the hydrocarbon is at least of the stoichiometric equivalent of the hydrogen content in the oil and is preferably from about -110% thereof.

Reaction zone 8 may be maintained at a temperature of about 300-625" F. and preferably 350-500" F. The residence time will vary with the temperature employed but should be such that the mixture is still liquid when removedtherefrom. It is preferably agitated or otherwise mixed to produce the uniform mixture.

The uniform mixture of sulfur and hydrocarbon is passed through line H and pump I5 into thereaction zone It. It is injected by any suitable means into the top of the reactor in such a way that a fine spray comprising droplets is formed. Inorder to avoid carry out of the droplets, line l4 may extend into reactor it. The reactor may be partially or entirely jacketed as illustrated, a heated heat transfer fluid being passed through the jacket in order to raise the temperature toa point within the range of about 625-1800 F. and preferably about 900-1500" F. This reaction zone it may be constructed of any suitable corrosion resistant material. During the residence ofthe particles in the reaction zone they are converted, at the high temperatures used, to the hard, insoluble, infusible, amorphous particles above referred to. Hydrogen sulfide is evolved together with minor amounts of other sulfur-containing reaction products. The gases comprising principally hydrogen sulfide is removed through line I! and valve 18. According to a preferred method, a portion of this gas is passed through line i9 and valve 20 to heater 2! wherein it is heated to a temperature above that maintained in reaction zone 46. Any suitable type of heater may be used including a pebble type heat exchanger or a tube and furnace heater having a source of heat not shown. The hot gases pass through line 22 and valve 23 being- 3 returned to the reaction zone [6. The hot gases serve the dual purpose of supplying heat to carry out the second stage of the above described reaction and produce the sulfocarbons, as well as to maintain the droplets and solid particles; in suspension in a fluidized condition until the conversion is complete. The particles should be maintained in a relatively dense phase so that little or none are carried out. of the. reactorr.

The dense, solid particles fall into the leg 24 of reaction zone is and may be withdrawn through line 25 and valve 26 to line 2T. Here they mix with sulfur vapors supplied from sulfur vaporizer 28 into which sulfur is introduced by way of line I 1, line 29 and valve 39-. Fhe mixture of sulfur vapors and sulfocarbon pass through valve 3i to reactor 32. If desired, a preheater 33 may be introduced into line 27 to raise thetemperature sufiiciently to carry out the subsequen reaction.

The solid particles are maintained in a fluid ized condition in reaction zone 32 wherein the carbon content of the sulfocarbon is converted substantially completely into carbon disulfide. At this point also the particles should be maintained in a dense phase effecting as little carry over as possible.

The vaporous reaction products pass through line 3%, valve 35 into a cyclone or other suitable separator 36. with ash that may have been contained in the sulfocarbon is removed through line 37 and valve 38. If desired, a portion or all of this may be returned to reactor 3' through line 39 and valve 4! The reactor contains a draw on line ii controlled by valve d2, through which a portion of the solids contained in the reaction zone 32 may be removed. Any heavy unreacted or unreactable material can be removed in this way. The vapors from cyclone pass through line 23 and valve t l to a condenser This is operated at an appropriate temperature above 525 F. and preferably 900-l-5GW whereby the sulfur is liquefied but is in a fluid condition rather than viscous form. The mixture then passes through line to separator ii. The sulfur is Withdrawn through line 2 and a portion of it may be re: moved from the system through valve remainder passes through line and valve 5%, pump 52 and may be recycled to reaction zone 8 through line t. The vaporous reaction productsare removed from separator A l, through line 53; and valve 54 to fractionator is separated the hydrogen sulfide and re: covered through line 55 and valve 5'? which maylead to an appropriate cooler and storage tank not shown. The gaseous products consisting principally of hydrogen sulfide is removed through line pump 59 and valve E30 to the sul-v fur recovery system 6 i. This may be any suitable system such as the so called Claus system wherein the hydrogen sulfied is burned in the presence of a catalyst, with air from line 52 and valve 63 to produce sulfur. The process may also be noncatalytio although in this case conversion to sulfur is usually less complete. The mixture of sulfur vapors from zone iii pass through line $4 and valve 65 to separator 65. Water vaporsand other gases are removed through line 87 and valve 68. The sulfur which is generally in liquid form may be removed through line 69 and valve l0 joining with line 59. The temperature should be keptat a point at which the sulfur is freely fluid instead of the highly viscous form. As an alternative a Finel divided carbon together The Carbon (ii-sulfide;

part of the sulfur may be supplied to the sulfur heater 28 by means not shown.

If the reaction temperature Within zone I6 is carried at about 1000-1800" F., the major portion of the hydrogen sulfide is evolved therein. This may be passed through line H and valve 12 to line 13 and valve is joining with line 58 and thus passed to the sulfur recovery system.

a further alternative an inert gas may be passed through line and valve i6, pump 11, joining withl-ine It and serve as a heat exchange medium and to fluidize the reacting mixture Within; zone [16.

In one preferred operation a portion or all of the hydrocarbon oil' from line I is passed through line 1:3; containing valve it to a scrubber Bil. Here it flows counter-current to upwardly rising sulfur vapors introduced. through line 8! and valve 82. In this way the sulfur. is absorbed in the hydrocarbon and. the mixture may then be pumped through line 83, valve 34, pump 35, valve 86 and line 8.! which joins with line 4 and thus introduced into the primary reactor 8. If desired, the temperature within zone 8. 3 ma be maintained in the neighborhood of 300-625" F.

According to another alternative, a part of the mixture of sulfur and oil may be passed through line 33- and valve 8% through line it to reactor 8.

According to another preferred embodiment, a, part of all of the hydrogen sulfide from line H may be, passed through line til and valve 5-!- into the bottom of scrubber in order to remove any sulfur that may be contained in the efiluent gases from reactor IS in the hydrocarbon oil and to preheat the oil in this reaction zone. This operation may be'carried out whether the elemental sulfur is introduced through line 8| or whether it is introduced; directly into, reactor 8 through line H2.

The scrubbed gases from scrubber 89: are passed through line 532 and may pass then through line 53 and valve Ed, joining with line 58. to the sulfur recovery system.

According to a still further embodiment the gases from line H may be passed through pump 95, line 96 and valve 9! to a high pressure fractionator 9 8. Gases from line :58 may be passed through line so and valve ill to high pressure fractionator 98; They may be compressed to pressures of the order of 100400 pounds per square inch in orderto effect separation or the carbon disulfide and the hydrogen sulfide. The carbon disulfide may be removed through line H11 and valve I02 to storage. The gases'corn; prising; principally hydrogen sulfide are removed through line I04 and valve H35 joining with line 13' a thu p sse o th s f r r cov ry s stem 6i.

This process is particularly advantageous be; Qause it provides a h d y which he sil iocarbons may be continuously manufactured a form wherein they are particularly susceptible to ready reaction with sulfur vapors for the pro duction of carbon disulfide. It also provides means by which the hydrogen sulfide produced the various stages, of the process and the $111:- furthat is. carried through unreacted can be re; covered and continuously recycled.

The continuous feature of the process is of a special advantage in view of the fact that the conventional type of carbon disulfide. process em.- ploys solid granular or lump carbonaceous ma-. terialsand is of a batch type. According to the conventional process, a batch of carbon particles isiintroduced into a stationary reactor and sulfur vapors passed therethrough until the carbon has been reacted to the desired extent. It has the disadvantage that large reactors must be employed and that they must be frequently shut down for cleaning and recharging. In the conventional type of reactor the particles of carbon gradually diminish in size forming a dust which tends to block the reactor and lines necessitating shut down in many instances long before the carbon has been completely consumed. Continuous processes of the present type are not adaptable to use with the conventional solid carbon particles but the process is peculiarly adapted to the hard dense carbon formed in the first stage of the present process.

I claim as my invention:

1. A process for producing carbon disulfide which comprises atomizing a uniform liquid mixture of a heavy hydrocarbonaceous material and elemental sulfur into a reaction zone, the proportion of said sulfur being at least 60% of the stoichiometric equivalent of the hydrogen con tent of said material, maintaining said zone at a temperature in the range of about 1000-1800" F. thereby to convert the droplets of liquid into a hard infusible, insoluble, amorphous substance consisting essentially of carbon sulfur and hydrogen in chemical combination, maintaining the particles in fluidized condition, continuously withdrawing a portion of the particles, mixing them with sulfur vapors and converting the carbon therein to carbon disulfide.

2. A process for producing carbon disulfide which comprises atomizing a uniform liquid mixture of a heavy hydrocarbonaceous material and elemental sulfur into a reaction zone, the proportion of said sulfur being at least 60% of the stoichiometric equivalent of the hydrogen content of said material, maintaining said zone at a temperature in the range of about 1000-1800 F. thereby to convert the droplets of liquid into a hard, infusible, insoluble, amorphous substance consisting essentially of carbon, sulfur and hydrogen in chemical combination, maintaining the particles in fluidized condition, continuously withdrawing a portion of the particles, mixing them with sulfur vapors and converting the carbon therein to carbon disulfide, in a reaction zone wherein said particles are maintained in fluidized condition.

3. A process for producing carbon disulfide which comprises atomizing a liquid mixture of a heavy hydrocarbonaceous material and elemental sulfur into a reaction zone, the proportion of said sulfur being at least 60% of the stoichiometric equivalent of the hydrogen content of said material, maintaining said zone at a temperature in the range of about 1000-1800 F. thereby to convert the droplets of liquid into a hard, infusible, insoluble, amorphous substance consisting essentially of carbon, sulfur and hydrogen in chemical combination, maintaining the particles in fluidized condition, continuously withdrawing a portion of the particles, mixing them with sulfur vapors and converting the carbon therein to carbon disulfide in a reaction zone wherein said particles are maintained in fiuidized condition, separating the vaporous reaction products from the last mentioned fluidized zone, recovering carbon disulfide, separating hydrogen sulfide and converting it into elemental sulfur and recycling the elemental sulfur thus produced.

4. The process of claim 3 wherein hydrogen sulfide is recovered from the first mentioned reaction zone and in the second mentioned rears-- tion zone is converted to elemental sulfur and the elemental sulfur is recycled to the first mentioned zone.

5. A, process for producing carbon disulfide wherein the liquid hydrocarbonaceous substance is uniformly mixed with elemental sulfur in proportions at least 60% of the stoichiometric equivalent of the hydrogen content of said hydrccarbonaceous substance, introducing the liquid mixture into a heated reaction zone in theform of droplets, maintaining said reaction zone at a temperature in the range of about 1000-1800 F. thereby converting the droplets into solid particles, removing hydrogen sulfide from said zone, heating a portion of said hydrogen sulfide, returning the heated portion to said zone thereby maintaining the droplets and solid particles in said zone in fluidized condition, continuously withdrawing a part of the solidified particles, mixing them with elemental sulfur vapors, converting the carbon therein into carbon disulfide in a reaction zone maintained at a temperature of about 11001800 F., said particles being maintained in fluidized condition, removing the vapors from said zone, separating solid entrained particles from said vapors, condensing, separating and recycling unconverted elemental sulfur, fractionating the vapors to separate a hydrogen-sulfide containing gas from the carbon disulfide, recovering the carbon disulfide, subjecting the hydrogen sulfide together with the portion of hydrogen sulfide from the first mentioned reaction zone which was not recycled as heat transfer gas to oxidization, thereby converting it to elemental sulfur and recycling the elemental sulfur formed.

6. A process for producing a carbon disulfide which comprises producing a uniform mixture of a hydrocarbon and elemental sulfur which is liquid in the range of about BOO-625 R, the proportion of said sulfur being at least 60% of the stoichiometric equivalent of the hydrogen content of said material, injecting the mixture in the form of liquid droplets into a reaction zone maintained at a temperature of about 1000-1800 FL, thereby converting the droplets to solid particles, maintaining the solid particles and droplets in fluidized suspension introducing a preheated gas into said zone to supply heat and to maintain said particles and droplets in fluidized condition, separating solid particles, continuously mixing them with vapors of elemental sulfur, converting the carbon in said particles into carbon disulfide, recovering the carbon disulfide, separating hydrogen sulfide containing gas from the first mentioned reaction zone, scrubbing said gas with at least a portion of the hydrocarbon charge, passing the hydrocarbon charge thus used as scrubbing material to the process, separating thescrubbed hydrogen sulfide gas, converting it to elemental sulfur and recycling the elemental sulfur to the process.

BERNARD W. GAMSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,081,576 Carter May 25, 1937 2,092,386 Baehr Sept. 7, 1937 2,330,934 Thacker Oct. 5, 1943 2,443,854 Ferguson June 22, 1948 2,447,003 Gamson Aug. 17, 1948 

1. A PROCESS FOR PRODUCING CARBON DISULFIDE WHICH COMPRISES ATOMIZING A UNIFORM LIQUID MIXTURE OF A HEAVY HYDROCARBONACEOUS MATERIAL AND ELEMENT AL SULFUR INTO A REACTION ZONE, THE PROPORTION OF SAID SULFUR BEING AT LEAST 60% OF THE STOICHIOMETRIC EQUIVALENT OF THE HYDROGEN CONTENT OF SAID MATERIAL, MAINTAINING SAID ZONE AT A TEMPERATURE IN THE RANGE OF ABOUT 1000-1800* F. THEREBY TO CONVERT THE DROPLETS OF LIQUID INTO A HARD FUSIBLE, INSOLUBLE, AMORPHOUS SUBSTANCE CONSISTING ESSENTIALLY OF CARBON SULFUR AND HYDROGEN IN CHEMICAL COMBINATION, MAINTAINING THE PARTICLES IN FLUIDIZED CONDITION, CONTINUOUSLY WITHDRAWING A PORTION OF THE PARTICLES, MIXING THEM 